Conventionally, there is known a gas treatment device using plasma. A gas treatment device of such a type can be used for decomposing and detoxifying various air pollutants such as VOC (Volatile Organic Compounds).
The inventors have proposed a gas treatment device that employs electric discharge and microwave radiation in combination (Patent Documents 1 and 2). For example, the gas treatment device disclosed in Patent Document 2 generates a small-scale plasma by means of a spark discharge and microwave pulses are radiated to the plasma. The energy of the microwave pulses is supplied to charged particles in the plasma, thereby enlarging and growing the plasma.